


Lyin' Eyes

by violentincest



Category: Captive Prince - C. S. Pacat
Genre: Alternate Universe - Canon Divergence, Anal Sex, Angst, Arranged Marriage, Auguste (Captive Prince) Lives, Enemies to Friends to Lovers, Infidelity, Kissing, Laurent cheats on Damen with Kastor, M/M, Oral Sex, Top Damen, Top and bottom Kastor, Top and bottom Laurent, eventual happy ending (probably), i'm really just winging this and these tags i'm sorry, is it really cheating though if your marriage was arranged?, possible bottom Damen, sibling sharing (later on) no incest planned for now but may change
Language: English
Status: In-Progress
Published: 2018-12-13
Updated: 2018-12-13
Packaged: 2019-09-17 14:19:37
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,335
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16976181
Author URL: https://archiveofourown.org/users/violentincest/pseuds/violentincest
Summary: Laurent is arranged to be married to Damianos, but he meets Kastor first. The two hate each other at the beginning, and slowly begin to fall for one another. Laurent cannot ignore his duty, and marries Damen, telling himself that nothing would ever happen between him and Kastor, until one day it does.





	Lyin' Eyes

**Author's Note:**

> Hello everyone! So my life has been crazy busy recently and I've been trying to write this for the past few months or so but haven't had much motivation. I wanted to make it a long one shot, but figured if I posted the first part, I'd be motivated to keep going. Let's see how it goes!
> 
> Warning: This is an infidelity fic, but it is NOT Laurent cheating on Kastor. It is Laurent cheating on Damen. I repeat this is Laurent cheating on Damen WITH Kastor. If that bothers you, don't read. If you still read it, and don't like the pairing, too bad. I warned you. Also, I haven't written the rest yet. As of now I plan for it to end happy, but no promises. If this bothers you too, again, don't read.
> 
> Dedicated to all of the other Kastorfuckers in the Capri discord. Love you all.
> 
>  
> 
> Beta'd by me, and me alone, so all mistakes are mine.
> 
> Enjoy, and if you like it let me know below (might encourage me to write faster).

Kastor didn’t truly know, and probably never would, if he had stabbed his brother on purpose all those years ago. He liked to think that he didn’t. That he would never want to gravely injure, or kill his brother, but part of him was upset then. He was furious that this child came around, years after him, and stole his chance at the crown. Upset that since Damen was getting older, people were listening to his advice and ideas as the future King. Kastor was thrown to the background. His opinions weren’t as important anymore. He would never know if that was the true reason for why he lost control of his sword. What he did know was that it would never happen again. After he felt the sword slice through his brothers flesh, he had never been more scared in his life. To see his younger brother, lying in the dirt, tears running down his cheeks as he bled out. Kastor kneeling next to him, calling out for guards, physicians, anyone as he tried to stop the bleeding. He swore to himself that night, that no matter what, no matter how envious or hateful he became, he would never do anything to hurt Damen again. 

*******************************

Kastor stood below the steps with his father as Laurent of Vere rode up to their palace. He was seated upon a Bay Mare. The coat was a shiny brown, it’s black mane tied into a braid, that matched the blonde one thrown over Laurent’s shoulder. Three men were with him. One to either side of Laurent, and one behind him. They slowed down as they came closer to the stairs. Once stopped, Laurent got off of his horse, reins in hands. One of the stable hands came to take them from him.

“Just see him to the stall, and give him some water. I’ll be by later to brush and feed him.”

The stable hand bowed, and left with his horse.

Laurent walked over to the King, and bowed. “Your Highness. Thank you for having me.” He then turned to Kastor. “Prince Damianos. It’s a pleasure to meet you.” He finished, in accented Akielon.

Kastor frowned, but didn’t answer, leaving it up to his father.

“Prince Laurent. Welcome to Akielos. I’m sure the journey has left you tired. This is my first son, Kastor. Unfortunately, Damen won’t be back for about a week. There was some more unrest on the border of Vask, as you may be aware of. He rode out with his Kyros to check on it. I told him to let his brother go, since you were arriving soon, but he said as future King he should be the one to do it.”

Laurent shook his head. “It is no problem. My brother has been seeing to those matters also. It is good for the people of the Kingdom to see their future King taking charge. I will wait for him patiently.”

“Kastor will show you to your room, and make sure that you are settled in. If you are not too tired, he can also take you for a tour around the palace. If you are we will see you again at dinner.”

“Thank you.” Laurent said, and then turned to Kastor, who was looking at him with an unpleasant expression.

“This way.” Kastor said starting up the stairs.

When Laurent had first gotten down from his horse, he had quickly looked around for Damianos. He had been afraid his betrothed was going to be ugly. He heard about Damianos’ prowess, but then again, anyone would do anything to sleep with a Prince, even if they weren’t handsome. When he layed eyes on Kastor, his fears were placated. The man was tall, but not too much. He had black hair, that reached his ears, and a short beard. His chiton didn’t hide much, and Laurent could see that he was well built, but not overly so. He was happy to have a good looking husband. Then he found out that this was the bastard, and not Damianos.

Laurent quickly followed him, catching up. They began to walk down the hall in silence.

“Your palace is nicer than I imagined.” Laurent said, figuring he should not insult one of his hosts.

Kastor snorted. “Please stop. I cannot take your accent. You’re butchering our language.”

He paused, a bit caught off guard, and then his eyes narrowed. “Like a bastard could do any better.”

“Maybe not any bastard, but this one can.” Kastor said, switching over to flawless unaccented Veretian. “Our father made sure that we could correctly understand the language of our enemy.”

“Former enemies. We are enemies no longer.” Laurent replied.

Kastor chuckled. “Sadly. I would have prefered we were. I have heard many stories about you Venetians. You are slippery, and slimy like snakes. Damianos is quick to trust, but I am not. I will be watching you until I am sure you’re harmless.”

“One thing I’m not is harmless.” he said with a pause, “but for my brother’s sake, I would never throw this alliance.”

“This is your room.” Kastor said ending the conversation abruptly. He looked Laurent over quickly, stopping outside of a door. “You’re my brother’s type. He will like you. Doesn’t mean I have to. Also, I know how Vere feels about bastards. As long as we look like happy in-laws in public we don’t have to pretend in private.”

“Good. Holding up pretenses all of the time is too exhausting. You may go then. I don’t need you for anything else.”

“I’ll send a slave to get you for dinner.”

“No. I won’t be having slaves attend to me. That is a barbaric practice that I will never get behind. Bastards though, I don’t mind bossing around. Get me yourself.” he said before opening the door. He walked into the room, shutting the door in Kastor’s face.

Sitting at dinner, Laurent had a realization. His Akielon was shit, not that he would ever admit it. His father and brother had both told him to study. They said it was good to know the enemies language, but he didn’t see any reason for that. If anyone was going to converse with the enemy it would be either of them, so he studied enough. Enough that the tutor saw him working, and trying, and wouldn’t tell his father. Sitting here, fluent Akielon flying past him, he couldn’t keep up. By the time he comprehended something, and wanted to comment, they were already onto a new topic. So, he just stuck to requesting more food or water, only saying something if someone tried to converse with him, which thankfully wasn’t a lot when they realized he didn’t really want to talk. Theomedes seemed to know Veretian, and Kastor was well versed, so he assumed Damianos knew it also. But he didn’t want to be dependant on Damianos for everything, and he also wanted to be able to have a say in matters when Damianos, and he, took the throne. He would need to start studying as soon as possible. As soon as he finished eating, he excused himself, so that he didn’t feel inadequate anymore.

“Did you sleep well last night?” Theomedes asked, the next morning at breakfast.

Laurent nodded. “Yes. The room is very comfortable.”

“You had everything you needed?”

He nodded again, and took a sip of his water. “Yes. Well almost everything. I like to read before bed, but I didn’t bring any books with me. I assume you have a library?”

“Yes of course! We have a grand library. Sadly, neither of my children make much use of it. Kastor can show you after breakfast. Right Kastor?”

He rolled his eyes, head down, looking at his food. His father couldn’t see, but Laurent could. “Of course Father. My pleasure.”

“Great. Now, I have some work to finish up. I will see you two later.” Theomedes said, pushing out his chair, and leaving the room.

They finished their breakfast in silence. Eventually, Kastor stood up, chair scraping loudly in the quiet of the room. “Let’s go.”

Laurent got up. “Yes, it must be such a disservice to show your brother’s fiancé around his new home.”

“That’s what we have slaves for.”

“It’s called….”Laurent paused. “Hospitality. At least we have that in Vere.” he said switching to Veretian, not knowing the word for hospitality. 

“We do too. We just normally don’t waste it on snakes.” 

He led Laurent to the opposite end of the Palace. He expected a library, but when Kastor opened the door he was shocked. There were rows upon rows of books. Way more than he thought there would be. It rivaled their library back in Vere.

“I’ll leave you to it.”

“Wait,” Laurent said. “I need….do you have books on education?”

“What kind of education?”

He sighed. He didn’t want to tell Kastor, but it would take him forever to find the books in here He had no idea how things were organized.

“I want to brush up on my Akielon.” 

“Damen speaks Veretian.”

“Yes, but the rest of the court doesn’t. One day I will be King alongside Damianos, and I should be able to communicate adequately with the citizens.” 

“Well, to start with, try only speaking Akielon. We’ve only been talking for a couple of minutes, and you’ve already reverted back to Veretian.”

“You said my accent was thick, and also I….” he wrinkled his nose in displeasure. “I don’t have the vocabulary.”

“Your accent will disappear with practice, and your vocabulary will improve. Come on.” Kastor said, and began to walk towards the stacks. He walked a few rows back and then stopped. “There are some Akielon language books here, and children’s books. They’re good for practice.”

Laurent looked at the row. This narrowed it down, but there were still many. “What did you and Damianos learn from?”

Kastor pulled out a couple of textbooks, and one of the children’s stories. “This one was Damianos’ favorite when he was younger. I’m sure he’d like it if you read it.”

“And yours?”

He paused. “Why?”

Laurent shrugged. “I’d like to see what you found interesting, after all you’ll be my brother-in-law.”

Kastor pulled out another book, and added it to the pile. He then dropped the pile in Laurent’s hands.

“Well, if you really want to learn you're going to need a lot of practice to get rid of that horrific accent. If you speak to me in Veretian again, I’ll pretend not to hear you. Only Akielon from now on." Kastor let out a sigh. "The things I do. My brother can't say I never helped him out with anything.”

Laurent glared, but the other made a good point. "Alright."

“There’s a couple of desks over there.” he said pointing to the far wall. “There’s some paper and pens in them. Good luck.” he said. Kastor began to walk away from him, and then paused. “And if you have any questions, I guess you can ask me. Just make sure they’re not stupid ones. I would hate for you to waste my time.”

After he left, Laurent carried the books over to one of the desks and sat down. He didn’t move again until a slave called on him for lunch. Once he finished, he went right back to studying. By the time dinner came, he had sheets full of notes, and another sheet just for questions. 

While they dined his eyes kept flicking to Kastor and back. He wanted to ask him so many questions, but didn’t want to embarrass himself by asking in front of everyone else. After the meal was over, Kastor turned to him.

“Once you retire from the baths, come to my room.”

Laurent spluttered. “Your room!? Did you forget I am promised to your brother, not you? Plus, I would never spread for a bastard.”

Kastor laughed. “You would count yourself lucky if I allowed you into my bed, but I have no desire for you. I saw you looking at me at dinner. I know you have questions, but are too prideful. I’ll answer them there.” He got up. “In my bed….really.” he said disbelievingly. “I’d tear you in two.” 

Laurent huffed, and stormed away to hide the blush forming on his cheeks.

After he bathed, he put on his nightclothes, a jacket over them, so that he didn’t look underdressed. He walked to Kastor’s room, and Kastor’s guards quirked their eyebrows at him when he knocked on the door.

“We are not doing anything untoward.” he said.

They just smirked.

Laurent entered when he was given permission, and left the door half open, to prove his point to the guards. 

They spent a few hours going over Laurent’s notes and questions until Kastor finally kicked him out. The next couple of days went about the same. One day the weather was really nice, and Kastor had an afternoon off, so they sat outside in the garden. Laurent pointed at plants, flowers, and insects. Kastor taught him their names.

“Your accent is already getting better.” Kastor said, after Laurent requested they take a break to have a snack. “I can actually understand what you’re saying.”

Laurent threw a cube of cheese at his face. It missed, and bounced off of Kastor’s chest, and onto his lap. “You were able to understand me before. You were just being an incorrigible ass.”

Kastor laughed, and picked the cube off of his lap, popping it into his mouth. “Yes, but it’s beginning to sound more natural. Damen will be impressed.”

Laurent nodded and took a sip of his water looking around the garden. “It’s beautifully done.”

“It was made in honor of Damen’s mother, after she died.”

“About that...aren’t you angry he took all of this away from you?” he asked, gesturing towards the palace and the grounds with his cup.

“I used to be. When he was born I was excited to have a younger brother. I could teach him to wrestle, to fight, and when he got older about women. Then he began to grow, and I was pushed to the side by everyone. I was angry for a long time, but….I love him. More than I love the idea of ruling. What about you and your brother?”

“Auguste is legitimate, and was born first. It’s different. He was always meant to rule. I was always meant to help. Now, I’ll end up ruling, even if I don’t want to. You will never have that opportunity.” Laurent closed the book they were studying with. ‘“It’ll get dark soon. Let's head in before the mosquitoes come out.”

Kastor followed behind him quietly, thinking.

The next morning, Laurent went to the stables, dragging Jord with him. He was starting to feel stir crazy stuck in the palace for these past couple of days. 

“We shouldn’t go too far. We don’t know the lay of the land well enough.”

Laurent was redoing the braid on his horse. “I know. I just need to ride for a bit.”

“Alright. I’ll grab my horse then.” he said turning to leave.

“Do all Veretian’s doll their horses up like that?”

Laurent turned his head, catching sight of Kastor. “No. I just like mine to look well groomed.”

“It looks like a pansy.”

He quirked his eyebrow. “I bet my pansy horse can still go faster than yours.”

Kastor laughed. “I doubt it.”

“Want to bet?”

“What’s the wager?”

Laurent paused thinking. “We don’t know each other well enough yet for a juicy wager. How about the loser owes the winner a favor, the winner can call it in anytime.”

“Deal.”

Laurent turned towards Jord. “Have a small bag of water packed. I’m going out with Kastor.”

“Do you think that’s a good idea?”

“Why not? He knows these lands, and I’m sure he’ll make sure nothing happens to me.”

Jord stared at Laurent for a minute Laurent staring right back “Fine.” he finally said reluctantly.

Kastor led his horse out of the stable. It was big, more like a war horse than a riding one. It’s black coat was shiny showing that he also took good care of it. He began to brush it as they waited.

Jord came back with a pack. “There’s water and food in there just in case.”

Laurent took it, and attached it to the saddle. “Where are we racing to? I still don’t know the land well. Keep that in mind.”

“The woods.” Kastor said, pointing to the barely visible line of trees. “It’s just a straight shot, so you can’t blame your loss on your lack of knowledge.”

Laurent looked at Kastor. “You’re going to ride, in that?” he asked, pointing to Kastor’s chiton.

Kastor looked down at himself. “Of course. These are my clothes. What else would I wear?”

“Yes, but I mean for riding. Wouldn’t...it’s um...you’re….” he blushed and shook his head. “Nevermind. Just mount your horse, you’re wasting time.”

“You’re the one who went off on a tangent.”

Laurent averted his eyes as Kastor climbed up onto his horse, then got on his own. “Jord, count us down.”

Jord sighed. “On your marks, get set, go.”

They both shot off before the last word was fully out of his mouth. Laurent let Kastor get ahead of him. The chase was the fun part. As the woods began to get closer and closer, Laurent leaned down and whispered, “C’mon girl. Time to bring us home.” and dug his heels in a bit. His horse picked up speed, and they just managed to pass Kastor before reaching the finish line.

Laurent slowed his horse, still laughing. The wind in his hair, and his face felt good after a few days without it. Kastor stopped next to him, and looked over. Laurent was still grinning.

“Congratulations, I underestimated you.” 

“And I you.” Laurent said. “If I knew it’d be that hard to catch up with you, I would have closed the gap sooner. You were almost victorious.”

Kastor climbed off his horse, Laurent eyes going to the flash of upper thigh that was revealed. “Come on. Let’s get our horses some water.” Kastor said.

Laurent got off of his and followed Kastor through the woods, leading his horse by the reins. 

They arrived at a small clearing, a lake in the center. Kastor let go of his horse’s reins, and the horse walked over to the water.

“Aren’t you afraid your horse will run off?”

“No. If he does he’ll end up back at the palace later on. He ran away once, when he was younger. Came back two days later wanting treats. He knows where the good food is.”

Laurent tied his horse’s reins to a tree anyway, not trusting his in such a strange place. It was close enough to the water that she could dip her head in and take a drink. He turned around from tying the reins to see the top of Kastor’s chiton drop, hanging by the pin at his waist.

“What are you doing!?”

Kastor looked at him, quirking his eyebrow. “Going swimming?”

“Naked?”

“Well what else do you want me to wear? You’re telling me you're embarrassed? I heard what goes on at you court.”

“Of course not!”

“Alright then.” Kastor said, and unpinned the rest of his chiton letting it drop to the floor, not looking away from Laurent.

Laurent’s eyes trailed down Kastor’s body, he was fit from all the sparring, and they stopped between his legs. His eyes widened a bit. He was huge. Bigger than anything he’d ever seen in the Veretian court. He quickly turned his cheek, averting his eyes, flushed a bright red.

Kastor laughed. “You are embarrassed. Blushing like a virgin on their first night.”

Laurent didn’t say anything.

Now it was Kastor’s turn for his eyes to widen. “You are aren’t you?”

“I don’t see how that’s any of your business. Now, get in the water. You’re embarrassing yourself.” he said making a shooing motion with his hand, gaze still averted.

Kastor let the subject drop, turned around to head towards the lake. Laurent looked back, eyes trailing from his back to his ass. He could still see his length hanging between his legs as he walked. 

Kastor got into the water up to his waist before turning back around. “You coming in?”

“I don’t have any appropriate clothes.”

“That didn’t stop me. Come on. Our horses are resting, we should too. Or like speaking Akielon, can you not?” he said, trying to goad Laurent.

Laurent hesitated before spitting, “Of course I can swim!”

“I doubt it. Do I have to teach you everything? I feel like that should be your betrothed’s job.”

“I’m starting to hate you again.”

“Again? When did you stop? Now get in. I promise I won’t let you drown. I don’t want a war with Vere when that’s what we’re trying to prevent.”

Laurent threw his head back, looking into the air, deciding what to do. He sighed, “Fine.” 

He undressed leaving his undershirt, and underwear on. He folded them neatly, and put them into the saddle bag on his horse. Then, he walked to the water and stuck one foot in. “It’s cold!”

Kastor rolled his eyes. “Is not. You’re just a baby. Now, get in.” he said before splashing Laurent with water. Laurent tensed up, clenching his jaw to keep from screeching. He walked into the lake, up to his shoulders. If he went any further, his feet wouldn’t be able to touch ground anymore. 

“Just a little more. Do you need me to help you?”

“Don’t you dare touch me.” Laurent spat. 

Kastor tossed his hands up. “Alright. On your own then.” 

He moved his arms underneath the water for a bit, working up some courage. Finally he took one step forward, and then another, until his feet weren’t touching the ground anymore. As soon as the water touched his chin, and Laurent went into panic mode. He started kicking furiously, his arms slapping the water in panic, not making the situation any easier for him. Kastor came over, and grabbed him, getting punched in the neck by one of Laurent’s flailing hands.

“Ow! Calm down! You look like a fool. I have you.”

Laurent slowly wound down, panting. He narrowed his eyes, glaring at Kastor. “I was getting the hang of it!”

“You definitely were not. Stop with your pride, and just let me help you. No one else is here to witness it.”

Laurent snorted.

“And I promise I won’t tell anyone. Even Damen.” he said rolling his eyes.

“Fine. I’ll castrate you if you do.”

“You could try.” Kastor moved his hands to Laurent’s waist, so he could keep him up as he bobbed. “Now, kick your feet lightly , and move your hands and arms right under the surface of the water, palms turned towards the back of you.”

Laurent did as he was told, and Kastor slowly let go of him, until he was keeping himself afloat. “See you’re doing it.” he said putting his hands up in the air, to show Laurent he wasn’t holding him anymore.

Laurent grinned. “I told you I could swim.”

“No, that’s called not drowning. I’ll teach you how to swim eventually, but baby steps first.”

They spent a couple of hours in the water. Kastor teaching Laurent how to swim. He didn’t get any further than the first practiced stroke, but at least he wouldn’t die if he fell in a lake or river and no one else was around. 

Kastor got out, and laid down in the grass, in the sun, to dry off. Laurent followed him out eyes raking over his body again.

“What?” Kastor asked catching his eye.

“Nothing.”

He smirked. “See something you like?”

Laurent scoffed. “Just thinking you don’t look too shabby for an old man.”  
As Kastor was laughing, Laurent walked over to a tree, and sat down in the shade, not wanting to burn. 

When they both had dried off a bit, they rode back to the palace. Kastor gave his horse to the stable boy so that he could head to the baths, but Laurent stayed to take care of his horse by himself. When he was done, he went to take his own bath, before heading to the library to study for a bit.

“I received word about Damen.” Theomedes said, later that night at dinner. “He should be arriving with his Kyros sometime tomorrow.”

Laurent nodded. “I’m looking forward to meeting him.” he said going back to his food.

After, even though Laurent was tired from the taxing day, he went to Kastor’s room to study. They worked for a bit, before Laurent closed the book. He looked at Kastor, thinking.

“Done already?”

“Damen’s coming back tomorrow.”

“Yes. I’m sure you’re both looking forward to meeting each other.”

“I wish I had met him first.” Laurent said, without actually meaning to say.

“What do you mean?”

He shook his head. “Nothing.”

“So...we’re done for the night?” he tried again.

Laurent ignored him. “How do you say kiss me in Akielon?” 

Kastor smirked. “You haven’t even seen my brother yet.”

Laurent looked at him unamused. 

Kastor smirked and said it, Laurent repeating right after. Then he turned his head up to meet Kastor’s eyes, and said it again, this time louder and stronger.

Kastor’s eyes widened a bit, eyes flickering from the blue of Laurent’s, down to his lips than back up.

Laurent said it one more time, before leaning in, and closing the distance between them himself.

The kiss was chaste, and quick. One brush of the lips, than another, and another, before Kastor pulled away. “We can’t. You’re promised to my brother. I would never ruin that.”

“I know. Nor would I.” he said. “I just wanted to try it once.” Laurent climbed off the bed, collected his books, and left.


End file.
